<?php
/*
simple multiple inheritance example

       guest
      /     \
   admin   member
          /      \
       author    mod
             \  /
            editor

*/
return array(
    array(
        'parent_id' => 'guest', // Guest
        'child_id'  => 'admin', // Administrator
    ),
    array(
        'parent_id' => 'guest', // Guest
        'child_id'  => 'member', // Member
    ),
    array(
        'parent_id' => 'member', // Member
        'child_id'  => 'author', // Author
    ),
    array(
        'parent_id' => 'member', // Member
        'child_id'  => 'mod', // Moderator
    ),
    array(
        'parent_id' => 'author', // Author
        'child_id'  => 'editor', // Editor
    ),
    array(
        'parent_id' => 'mod', // Moderator
        'child_id'  => 'editor', // Editor
    ),
);